GIS-IDs: List of associated IDs on the GIS/data-source side.
Hyperlinks: Associate one or more web link, photo, word processing document, or other file with this element.
Air Volume (Initial): Volume of air near the valve at the start of the simulation. The default is zero. If volume is nonzero, the pressure must be zero.
Time to Close: For an air valve, adiabatic compression (i.e., gas law exponent = 1.4) is assumed.The valve starts to close linearly with respect to area only when air begins to exit from the pipe. If air subsequently re-enters, then the valve opens fully again. It is possible for liquid to be discharged through this valve for a period after the air has been expelled.
Diameter (Small Air Outflow Orifice): Diameter of the air outflow orifice (the orifice through which air is expelled from the pipeline) when the local air volume is less than the transition volume (TV), or the air pressure is greater than the transition pressure (TP) (depending on which trigger is used to switch the outflow orifice size). This diameter is typically small enough for the injected air to be compressed, which can help prevent severe transient pressures. Generally air flows out the large air outflow orifice for some time before switching to the small air outflow orifice for the final stages of air release.
Diameter (Large Air Outflow Orifice): Refers to the discharge of air when the local air volume is greater than or equal to the transition volume (TV), or the air pressure is less than or equal to the transition pressure (TP) (depending on which trigger is used to switch the outflow orifice size). This diameter is typically large enough that there is little or no restriction to air outflow. Generally air flows out the large air outflow orifice for some time before switching to the small air outflow orifice for the final stages or air release.
Diameter (Air Inflow Orifice): Diameter of the air inflow orifice (the orifice through which air enters the pipeline when the pipe internal pressure is less than atmospheric pressure). This diameter should be large enough to allow the free entry of air into the pipeline. If set to zero, this diameter is considered infinite (i.e. there is no restriction to air inflow).
Diameter (Air Outflow Orifice): Diameter of the air outflow orifice (the orifice through which air is expelled from the pipeline).
Transition Pressure: The local internal system air pressure at the air valve above which the transient solver switches from using the large air orifice to the small air orifice (in order to minimize transients).
Transition Volume: The local volume of air at the air valve below which the transient solver switches from using the large air orifice to the small air orifice (in order to minimize transients). This volume often corresponds to the volume of the body of the air valve.
Air Flow Curve (Small Air Outflow Orifice): Curve that defines discharge of air when the air volume is less than the transition volume (TV), or the air pressure is greater than the transition pressure (TP).
Air Flow Curve (Large Air Outflow Orifice): Curve that defines discharge of air when the air volume is greater than or equal to the transition volume (TV), or the air pressure is less than or equal to the transition pressure (TP).
Trigger to Switch Outflow Orifice Size: Select whether the transient solver switches from the large air outflow orifice to the small air outflow orifice based on Transition Volume or Transition Pressure.
Report Period (Transient): Number of time steps between successive printouts of operation. By default, this printout is suppressed.
Treat Air Valve as Junction?: Specifies whether or not to treat the air-valve as a junction element in steady state and EPS simulations. If false, the valve may allow part full flow subject to the prevailing hydraulic conditions.
Air Flow Curve (Air Inflow Orifice): Curve that defines orifice behavior for the injection of air into the pipeline.
Air Flow Curve (Air Outflow Orifice): Curve that defines discharge of air when the volume is greater than or equal to the transition volume (TV).
Air Flow Calculation Method: Choices: Orifice Diameter, Air Flow Curve
Elevation: Elevation at centroid of junctions, valves, and pumps; the ground elevation at tanks; the hydraulic grade at reservoirs.
Trace (Initial): Specify the initial trace amount at the current location.
Zone: Specify the zone for the element.
Concentration (Initial): Specify the initial concentration for the global concentration at the selected element.
Is Constituent Source?: If true then the selected node can inject a set concentration of the global constituent into the system.
Pattern (Constituent): Specify the pattern which dictates how the injected constituent concentration varies over time.
Concentration (Base): This data field allows you to specify the corresponding constituent concentration at this node over time.
Mass Rate (Base): This data field allows you to specify the corresponding constituent mass rate at this node over time.
Age (Initial): Specify the initial age of the fluid at the selected element.
Pressure: Calculated pressure at node.
Pressure Head: Calculated pressure head at node.
Hydraulic Grade: Calculated hydraulic grade at node.
Age (Calculated): Age at selected element for current time step.
Trace (Calculated): Trace at selected element for current time step.
Concentration (Calculated): Concentration at selected element for current time step.
Has Calculation Messages Now?: If true then the current element has associated calculation warning messages for the current time step.
Head (Maximum, Transient): Maximum head at node over the course of the transient simulation.
Head (Minimum, Transient): Minimum head at node over the course of the transient simulation.
Pressure (Maximum, Transient): Maximum pressure at node over the course of the transient simulation.
Pressure (Minimum, Transient): Minimum pressure at node over the course of the transient simulation.
Air Volume (Maximum, Transient): Maximum air volume at node over the course of the transient simulation. Not applicable to Reservoirs and Rating curves.
Vapor Volume (Maximum, Transient): Maximum vapor volume at node over the course of the transient simulation. Not applicable to Reservoirs and Rating curves.
